I've built three of Bruce's amps and all have been very satisfying projects. The GG Pre Amp and the SC150 Amp have been running for five years and the CCS Pre Amp running for four years. None of the amps has had a tube failure nor any component failures. Their sound is excellent.
Here's Sang's verison of a Bruce Rozenblit's Grounded Grid Pre Amp from Audio Reality.
Here's a look at her back side
I built a A/B speaker switch on the back to allow for switching between my Surrond Sound Receiver and the SC150.
Here's a look under the hood
The volume control is done with an Elma 2 pole 24 position shorting switch. Input selection is done with an Elma 2 pole 6 position shorting switch.